... clean leaking proof steel ball fitted at both ends, in case glass pipe broken nominal flage size: DN20, needle valve fitted ... purpose. Leaking proof steel ball fitted at both ends, in case broken of glass pipe.Nominal length: L=300, 500, 600 ... steelstainless steelfemale flangemale flangenominal lengthnonminal pressurenominal boreselection markers: (D,W)(A,B)(I,II),L=300-1,700, HG5